Its control method is actually very simple, just check it carefully according to the requirements of the specification. The key is self-inspection.
Concrete cracks are mainly about mastering raw materials and mixing; The stability of cement is poor, the volume shrinkage is too large during hardening, and the silt content of sand is large. The slump of concrete should not exceed 5-7.
If commercial additives are used, attention should be paid to slump, and plastic film should be used to cover the initial setting to ensure that concrete will not shrink cracks due to surface exposure or premature water loss caused by wind and sand disturbance.
In short, you can refer to the details.